Field of Invention
The present invention relates to a power electronic circuit. More particularly, the present invention relates to a packaging structure of a power electronic circuit.
Description of Related Art
Various operating electronic devices are associated and affect one another via electromagnetic conductance, electromagnetic induction and electromagnetic radiation, which, under specific circumstances may disturb the operating apparatus and personnel. The field electromagnetic compatibility (EMC) rising during the eighties focuses on solving the above-mentioned problem. According to the International Electro technical Commission (IEC), the definition of EMC is that the signal and disturbance may coexist without jeopardizing the information contained in the signal. This field focuses on investigating and solving the formation, propagation, receipt and inhibition mechanism of the disturbance and the corresponding detecting and quantifying technique, and, based on the above-mentioned basis, providing clear specifications regarding the standard for the generated disturbance, the standard for anti-disturbance and inhibitory measures, so that the devices within a same electromagnetic environment are compatible with one another, and meanwhile, will not introduce unallowable electromagnetic disturbance to any entity within the environment. With the wide application of modern electronic devices across the world, the inter-associability of various electronic devices also increases. In view of this, China, the United States, Europe and most other countries in the world has already stipulated or is currently stipulating relevant standards so as to limit the EMC of industrial and consumer electronic products. Accordingly, the requirement for electronic products to achieve the standards related to electromagnetic compatibility is also high. Currently, the certification of EMC mainly follows international standards such as FCC, CISPR, ANSI, VCCI and EN. These EMC standards targeting electronic products comprise two main parts; that is, the electromagnetic interference (EMI) and the electromagnetic susceptibility (EMS). The EMI primarily comprises Radiated Emission, Conducted Emission; Harmonic; and Flicker. The EMS mainly includes Electrostatic discharge (ESD), Radiated Susceptibility (RS); Conducted Susceptibility (CS), Drop in Power (DIP), SURGE, Electrical Fast Transient (EFT), and Power frequency magnetic field (PFMF). Moreover, different electronic products may correspond to different EMC standards. For example, in China, the radiation of domestic electronics should follow the EN 55014 standard, the illuminating electronics should be in compliance with the EN 55015 standard; while there are other EMS standards respectively for medical electronic devices and information technology (IT) apparatus. In most electronic devices, how to minimize the EMI disturbance is a critical design index; solving the EMI disturbance will not only consume vast amount of pan power and time, but is also difficult to amend once the design is fixed. Modern power electronic apparatus consists of power electronic components, which is a heavy power electronic circuit for converting and controlling industrial electric energy. First, during the operation, the heavy power electronic circuit would generate voltage and current signals with drastic changing rates, and these drastically changing voltage and current signals are strong sources of the EMI disturbance; next, the heavy power electronic circuits is spacious, and hence, it is difficult to shield the EMI disturbance; in view of the foregoing, it is more difficult to solve the EMI disturbance of power electronics. With the advancement of the power electronic semiconductor device, some novel semiconductor devices have been developed. These novel semiconductor devices have higher operating speed, and the application of novel components such as silicon carbide and gallium nitride in the power electronic circuit will generate voltage and current signals with more intense changing rates. This would also lead to a higher design requirement for power electronic apparatus. Therefore, a fast, convenient and effective approach to sole the EMI disturbance will become an important development focus for the power electronic apparatus in the future. In view of the foregoing, there is a need to provide a novel technical solution for fast, conveniently and effectively solving the EMI disturbance of power electronics.
The EMI disturbance is mainly composed of three parts: the source of EMI disturbance, the path of the EMI disturbance, and the object subjects to the EMI disturbance. Regarding the EMI disturbance resulted from the power electronic apparatus, the conventional method for reducing the EMI disturbance of the power electronic apparatus mainly focuses on reducing the source of the EMI disturbance and altering the path of the EMI disturbance to reduce the EMI disturbance. However, although conventional technique may effectively reduce the EMI disturbance of the power electronic apparatus, it requires additional cost and power consumption, or it may require experienced engineers to spend a lot of time for designing; additionally, the conventional method may not be completely effective in every case. Howe to fast, conveniently and effectively solving the EMI disturbance of power electronics is a problem remained to be solved.